Carbon holder



0 13, 1936- c. A. FUCHS ET AL' CARBON HOLDER Filed March 21, 1934 IN V EN TORS mar/es A. FuC/YJ Patented Oct. 13, 1936 2,056,963 cannon HOLDER Charles A. Fuchs,v Hollis,- N., Y., and Frank Spaloss, Teaneck, N. J., assignors, by mesne assignments, to Projector Improvement Company, Inc., New York, N. Y., a corporation of New York Application March 21, 1934, Serial No. viasss 2 Claims.

This invention relates to carbon electrode holders which form extensions of carbonstumps that are too short to be advanced by the feeding mechanism of lamps in which they are used. It is an improvement over that shown in our ap- 6 plication Serial No. 696,336, filed November 2,

1933, in which there is provided a gripping element partially enclosed in one end of a tubular body part to be protected thereby, into which element a reduced shank of the carbon is inserted,

and which gripping element is then manipulated, by a finger piece at the other end of the body part, to draw the gripping element in the same direction in which the carbon is inserted to thus cause suitable cams thereon which cooperate with the tubular body part to press resilient jaw members tightly against the shank of the carbon to firmly grip it and thus secure the holder to the carbon.

In the present invention the gripping element,

is wholly encompassed by the tubular body part and is pushed, by the finger piece at the opposite end, and in the direction opposite to that in which the carbon is inserted into the holder, and there is provided an interior, annular cam, at the carbon receiving end of the tubular body part, with which the free ends of resilient jaws of the gripping element engage to press them tightly against the shank of the carbon to grip it.

We have observed that where the cam portions or jaw elements project from the tubular body part, they have a tendency to grow or spread in a permanent deformation due to the influence of the heat from the carbon are. In order that the carbon saver operate efficiently, it must naturally be capable of use close to the carbon are, the heat of the latter causing deterioration of the resilient jaw elements. But the tubular body part being circularly continuous at its adjacent end, possesses greater strength and adaptability to withstand the heat of the carbon are, particularly if the wall at said end be thick.- ened. Nevertheless the carbon stick and the carbon saver are of the same diameter and provide a substantially continuous cylindrical surface that can pass through the feed rollers umformly and evenly.

Features and advantages will hereinafter ap-' pear.

In the drawing which forms part of the specification,

Figure 1 is a view, partly in section, of a holder attached to a carbon;

Figure 2 is a sectional view taken at the line 2 2 of Figure 1;

Figure 3 is a view, partly in section, showing another form of holder attached to the carbon; and

60 Figure 4 is a view, partly in section, of another form of gripping element and finger piece therefor.

Similar reference characters represent similar parts throughout the drawing.

I'he holder '8 includes a tubular body part 9 having an axially extending aperture ID at one end 5 into which may be inserted the reduced end H formed at the end of a carbon electrode I2. The end or shank H of the carbon is receivedby resilient or bendable arms or jaws I 4 extending from a body part 15 of the gripping element I6, 10 with the annular shoulder at the shank in abutment with said body part I5, as shown.

At the inner end of the aperture I0 there is provided an annular cam l'l against which the free ends of the jaws It may be thrust by mov- 15 ing the gripping element axially of the body part 9, to thus cause the jaws M to tightly grip that portion of the shank II which projects into the gripping element. When the gripping element is moved in the opposite direction, the free ends of the jaws I 4 move away from the cam l1 and spring away from the shank H to relinquish their hold on the carbon for the purpose of replacement. 25

It will be noted that the tubular passage I0 between the cam I! and the adjacent end of the body part 9 is of substantial length to afiord an ample guide for the carbon shank I I, and also to assure that the jaws M will be spaced sufficiently inward in the body part 9 for adequate. protection from the heat of the carbon arc. The wall of the body part 9 at the passage I0 is sufficiently thick for ample strength in withstanding the heat of the are, and in rapidly conducting away the heat at this end of the carbon saver, and to be of the same diameter as the carbon stick l2 in a continuously unbroken cylindrical arrangement therewith. It will be understood that the term carbon saver is used to denote a device 40 which can pass withthe carbon as a continuous electrode unit through the rollers of a feeding head'in a uniform, constant manner.

To push or pull the gripping element I6 axially of the body part 9 to grip or release the carbon 45 [2, there is provided a tubular stem l8 into one end of which extends a reduced portion IQ of the gripping element [6. Said reduced portion 19 is provided with an annular groove 20 into which extend reentrant portions 2! of the stem [8 to 50 form a connection between said stem and the gripping element.

At the other end of the stem there is provided a screw thread 22 which may be on a finger piece 23 secured to the stem by a pin 24. The thread 22 of the finger piece 23 engages an internal thread of the body part 9 so thatby rotating the said finger piece in one direction the stem I8 is pushed axially and in one direction of the body part 9, and when the finger piece 23 is rotated in 0 pulled axially of and in the opposite direction of the body part,

tween the stem l8 and gripping element [6 permits rotation of the stem independently of the gripping element so that the stem may be rotated,

after the gripping element has taken hold of the shank! l andgis arrested thereby, to tighten the gripping element on the carbon. 1 It will further beunderstood that by thisconstruction the carbon, while being attached to the gripping element, is moved slightly outwardly of the body part 9, thus avoiding any tension on the shank which may otherwise be produced if the carbon weredrawn inwardly dueto engagementof the shoulder of the carbon against the end of the body part. Consequently the carbon is less likely to break .at said shoulder. V I

, In a rnodified form of the invention the jaws Ma may be formed on the inner tube orstem I8a which is provided with a'finger piece 23a and has a pin 30 extending into a cam portion'3 l' of an L slot having an axially extending portion 32 also. Thus, it will be understood that by rotating the stem in one direction the pin 30 engages one side of thecam slot 3| to push the stern axially of the body part 9a and force thefree ends of the jaws Ma against the annular cam Ila and thus grip the shank no: the carbon l2. When'the stem I8a is rotated in the opposite direction, the p n 30 v e I to pull the stem l8d axially of the body. part 9a to draw the jaws 14a away from'the cam Nd and thus release the'carbon. The axially extending portion 32.0f the L-shaped slot' is provided to V 1 permit ready removal and insertion of the stem l8a. V V

In afurther modification, illustrated in Figure ithe gripping. element l6b may be formed at one "end of the tubular body part [8b, the opposite end being provided with-reentrant portions 2 lb to engage in a groove 2% formed on a'reduced portion 251) that may be integral with the finger piece 23b. Theoutside diameter of the stem 3b of Figure '4 may be smaller than the inside diameter of the body part 9 of Figure 1 and the gripping element may be of larger diameter than the stem ,and'fit into the body part 9 to move freely'axially therein, The finger piece 23b is provided with a thread 221) which may engage the internal thread at 1 the end ofthe body part 9 to cause, the free end of the resilient member or jaws lBb to engage the cam I! to grip the carbon;

. Thus, it will be understood that the gripping device and finger piece illustrated in Figure 4 form a cooperative device which may be used with the body part 9 instead of the gripping device and finger piece shown in Figure 1.

It will also be understood that the finger piece 23b maybe provided withthe pin 30 instead of the'screw thread 22b for use with the body part 9a-of Figure 3. j

In the preferred mode of operation, the carbon shank is inserted into the saver until the annular shoulder of the carbon abuts the open end of engages the other side of the cam slot 3| '7 the saver; whereby. the latter andthe-parbon are maintained in true parallel relation, after being V U s V secured together by the clutch. As the length' It will be understood that the gripping element' of the annular thickened part of the tube at I0 is pulled by the stem due to engagementiof the; portions 2| with a head 25 .at one side of the" groove 20. When, howeverl thelgripping elerrientf is pushed by the stem 18, the endlji of the s'tem engages the shoulder 21 of thegrippingelementfi- It will also be understood that connection 'be-" is relatively considerable, and approximately equal to the diameter of the shank, the carbon "may 'also be -maii1tained alined withthe saver, evenifgrowth-under heat of the part l0 occurs, because such growth is V convergent away from the e'ndiof the saver. In any case, however,

parallelism, which is the more important factor,

is'assured by the rigid, true seating of the carbon directly against the one piece tube 9.

While certain preferred embodiments of the invention have been shown; and-described, fitiwill I ing/aone piece tube adaptedto be engagedgby the rollers of a carbonfeeding head, said tube having an open end along a planeperpendicular to the tube axis, a carbon electrodeofsuniform diameter with thetube and having, a reducedend shank and having "an annular shoulder; atcthe shank lying along, a plane atright angles tothe axis of the electrode, ,said tube having the-end portion of its wall annularlyj thicknened, said thickened wall portion beingof a length lapproxi-r mately equaltothe diameter ofsaid shank, the

inner end of said thickened end portion having a cam surface, a clutch unit movable along-the inside of the tube toward said openend for.actu-.

ationby said cam surface, said shankbeing snug: 1y fitted in the thickened tubular portion and be.- ing releasably engageable byjtheclutchunit, said shoulder of the, carbon electrode having seating engagement with the thickened tubular ,portion along said planefor maintaining theoarbon electrode parallel to the tube, andthe thickened tubular. portion, bygvirtue of they length thereof, tending to ,aline the carbonwelectrode and thegtube irrespective of divergent growth, Of.SaldthiCk-'.

ened tubular portio 111.6 to heating thereof, and

said thickened portion being of uniformly equal outside diameter with the electrode, whereby .said electrode and tube can bereadily. continuously engagedby saidrollers.

2. A device including a carbon saver comprising a cylindrical tube having an openend-lying in;a.

plane perpendicular to the axis'of the tube the wall of the tube adjacent to,sai d open end-being cam surface, a clutch unit, in the tube movable therealQng toward said open endzforactuation by said cam surface, and a carbonfileetrode of the same outside ,diameteras thetubeand having a reduced end shankadapted to snugly pass '60 through said thickened wall portion for engage-' internally thickenedand proizidinganinternal 

